BN Seminar - Benoît Kornmann (ETH Zürich): "The push and pull of mitochondrial gymnastics: mechanical force in mitochondrial dynamics"





Room E, Applied Sciences building, Lorentzweg 1, Delft


Mitochondria form and extended intracellular network that is constantly remodeled by dynamic events such as mitochondrial fusion, fission and transport. Fusion and fission are catalyzed by enzymes that use the energy of GTP hydrolysis to facilitate membrane rearrangement. Transport is catalyzed by molecular motors that use the energy of ATP hydrolysis to move mitochondria around in the cell. Mitochondrial dynamics in the cytoplasm has to be coordinated with the dynamics of other structure, and with any variation in cell shape. 
In particular, during mitosis, cell shape is dramatically altered to allow the partitioning of cellular material in two daughter cells. We discovered a molecular mechanism allowing proper dynamics of the mitochondrial network in mitosis. Unlike other mechanisms, this one generates force neither from ATPase motors, nor GTPase fission/fusion factors.

Forces are also involved in mitochondrial fission. We show that mechanical stimulation of mitochondria causes them to undergo fission. Therefore mechanical trigger can lead to a biochemical response, and influence a major cellular membrane remodeling event.